Coffee is used worldwide and many types of coffee consumption are practiced where it is desirable to freshly grind the coffee to be used in order to improve the quality of the drink being consumed. Good examples include the preparation of espresso and espresso based drinks. Typically, to grind coffee, grinding burrs are used in pairs or sets and operate with one burr fixed from rotation and the other burr driven to rotate. The adjacent spacing of the burrs along the axis of rotation is adjusted to change the coarseness of the grinding action and yield the desired result. This applies to both conical and flat type burr sets.
Variables which can change the quality and rate of ground coffee output include the grind coarseness setting, physical properties of the coffee beans being ground, environmental conditions such as humidity, and the physical condition of the burrs.
In many coffee grinding applications, with espresso shops being a good example, the coffee may be ground for fresh use in single extraction amounts. Grinders in this use may cycle on and off with great frequency, grinding for only a few seconds in duration at a time. The desired output may commonly have a specific target amount in the range of only 12 to 24 grams of ground coffee per cycle.
The accuracy and reliability with which a grinder generates a desired quantity of ground coffee is important. A primary means of compensating for inaccuracy and lack of reliability is to grind an excess of coffee for each dose and discard what is not needed. The discard of excess coffee, dose by dose can increase the consumption of inputs and the ratio of expense to product. In the short duration, repetitive grinding process used in much espresso service, many variables are emphasized. These include the time and output resulting from motor spin up and wind down, the dislodging or retention of small quantities of ground coffee within the grinder.
One of the strategies for grinding to a target dose is to use a programmable timer to control the grinder motor. However, due to dose to dose variations in starting torque needed, spin up and spin down, and the irregular delivery of ground coffee from within the grinder, the timer-base approach has significant limitations and consequently the discard of excess coffee can remain significant. Thus, improved systems and methods for coffee grinding are needed.